Well, Bacteria are microscopic organisms whose single cells do not have membrane-bound organelles. The term, prokaryote, has become so widely used, that we commonly associate it with bacteria. Prokaryotes are unicellular organisms that lack a nucleus and can live in any habitat possible. They are 1/100th of a millimeter small, which is so small that you need to use a light microscope to see them.
Prokaryotic Cell
Prokaryotic Cell
The cell shown above is a prokaryotic cell. The 7 different parts each have their own function within the cell:
Cell Wall - Provides protection and allows for the bacteria to stick to bacteria or other cells.
Cell Membrane - Controls what enters and exits the cell.
Ribosomes - Makes proteins using DNA and RNA.
Pilli - Provides cell-to-cell contact.
DNA - Genetic information.
Flagella - Provides movement.
Peptidoglycan - A carbohydrate and protein molecule that is inside the cell walls of eubacteria. It is also a useful drug target.
Eubacteria Vs. Archaebacteria
Archaebacteria
Both
Eubacteria
NO peptidoglycan
Small
Peptidoglycan
DNA sequences of archaebacterial
Lack nuclei
Live everywhere
Live in harsh conditions
Cell walls, cell membranes, ribosomes, DNA
Most common/Largest kingdom of prokaryotes
Methanogens
Methanogens are a group of archaebacteria that live in oxygen-free environments, marshes, mud, cow intestines. They also produce mathane gas.
Scientific Name
Shape
Cocci
Spherical-shaped
Bacilli
Rod-shaped
Spirilla
Spiral and corkscrew-shaped
Cocci, Spirilla, and Bacilli
Other Important Facts to Note...
Flagella
Bacteria Movement
Some bacteria use flagellum, whiplike structures, while others lash, snake, or even spiral foward. There are other bacteria that glide along a layer of slime-like material that they create.
Aerobes and Anaerobes
Obligate anaerobes require a constant supply of oxygen to survive. Obligate anaerobes do not require oxygen to survive. Facultative anaerobes can survive with or without oxygen.
Bacteria Reproduction
Bacteria can reproduce approximately every 1-3 hours. Some can reproduce as quickly as 20 minutes.
Preventing Bacteria Reproduction
The availability of food and waste products prevents bacteria from reproducing out of control.
Bacteria Cell Division
The cell division in bacteria is called binary fission. Binary fission is when an organism replicates its DNA, divides in half, which produces an end result of two identical daughter cells. This process is also known as asexual reproduction. Isn't this process similar to the way eukaryotic cells reproduce?
Bacteria and Genetic Diversity
They perform conjugation, in which a hollow bridge forms between two bacterial cells, and genes move from one cell to the other. DNA is exchanged during this process. Conjugation can also occur between different species.
Conjugation Process
Spore Advantages A spore is a structure that is formed when the growth conditions become unfavorable. Spore formation is advantageous because they make it possible for some bacteria to survive harsh conditions. When conditions improve, bacteria become active again.
Bacteria can be beneficial...
Bacteria can be beneficial to our society by capturing energy by way of photosynthesis, breaking down the nutrients in dead matter and the atmosphere, and others can convert inorganic nitrogen into organic nitrogen.
Bacteria Cell
Here is a link to an animation about bacterial conjugation...
Bacteria
By Jake Naar
Someone may ask...What are bacteria?
Well, Bacteria are microscopic organisms whose single cells do not have membrane-bound organelles. The term, prokaryote, has become so widely used, that we commonly associate it with bacteria. Prokaryotes are unicellular organisms that lack a nucleus and can live in any habitat possible. They are 1/100th of a millimeter small, which is so small that you need to use a light microscope to see them.
Prokaryotic Cell
The cell shown above is a prokaryotic cell. The 7 different parts each have their own function within the cell:
Eubacteria Vs. Archaebacteria
Methanogens
Methanogens are a group of archaebacteria that live in oxygen-free environments, marshes, mud, cow intestines. They also produce mathane gas.
Other Important Facts to Note...
Some bacteria use flagellum, whiplike structures, while others lash, snake, or even spiral foward. There are other bacteria that glide along a layer of slime-like material that they create.
Aerobes and Anaerobes
Obligate anaerobes require a constant supply of oxygen to survive. Obligate anaerobes do not require oxygen to survive. Facultative anaerobes can survive with or without oxygen.
Bacteria Reproduction
Bacteria can reproduce approximately every 1-3 hours. Some can reproduce as quickly as 20 minutes.
Preventing Bacteria Reproduction
The availability of food and waste products prevents bacteria from reproducing out of control.
Bacteria Cell Division
The cell division in bacteria is called binary fission. Binary fission is when an organism replicates its DNA, divides in half, which produces an end result of two identical daughter cells. This process is also known as asexual reproduction. Isn't this process similar to the way eukaryotic cells reproduce?
Bacteria and Genetic Diversity
They perform conjugation, in which a hollow bridge forms between two bacterial cells, and genes move from one cell to the other. DNA is exchanged during this process. Conjugation can also occur between different species.
Spore Advantages
A spore is a structure that is formed when the growth conditions become unfavorable. Spore formation is advantageous because they make it possible for some bacteria to survive harsh conditions. When conditions improve, bacteria become active again.
Bacteria can be beneficial...
Bacteria can be beneficial to our society by capturing energy by way of photosynthesis, breaking down the nutrients in dead matter and the atmosphere, and others can convert inorganic nitrogen into organic nitrogen.
Here is a link to an animation about bacterial conjugation...
http://www.hhmi.org/biointeractive/animations/conjugation/conj_frames.htm